Victron Energy Quattro-II 2x120V Inverter/Charger (120/240 Split Phase)

The Victron Quattro-II 2x120V is a single-box 120/240V split-phase inverter/charger with two AC inputs. Connect both shore power and a generator (or two generators) directly to one unit - it automatically selects the active source - while delivering true North American 120/240V split phase, a fast adaptive charger, and clean pure sine wave inverter power from your battery bank when no source is available.

It carries all the capability of the MultiPlus-II 2x120V - PowerControl, PowerAssist, two AC outputs, anti-islanding for ESS, and VE.Bus communication - and adds the Quattro's defining feature: two independent AC inputs with an integrated transfer switch. Available as a 3 kVA unit at 12V or 24V DC. Choose your battery voltage from the variant selector above.

Two AC inputs - the Quattro difference

This is what sets the Quattro-II apart from the MultiPlus-II 2x120V. You can wire both shore power and a generator (or two generators) directly to the Quattro-II. It detects which source is live and switches automatically - no external transfer switch, no relays to size, no second enclosure on the wall. If you only ever connect one AC source, the MultiPlus-II 2x120V covers that case; if you run both shore and a genset, the Quattro-II is built for it.

How the 2x120V split-phase design works

When fed from a split-phase 120/240VAC source (shore or generator), the Quattro-II 2x120V feeds AC straight through - its output mirrors the input, giving you 120V on each leg (L1 and L2) and 240V across them. The inverter/charger connects to neutral and the preferred input line (L1), so battery charging current is drawn from L1.

When no AC source is present, the unit switches to inverter mode and produces 120V single phase, internally linking L1 and L2 so both sides of your distribution panel still receive 120V. 240V loads are only available when the unit is fed by a split-phase source - this deliberately prevents heavy 240V loads like a water heater or 240V air conditioner from draining the battery bank while you're off shore power. The L1 output transfers in under 18 milliseconds (UPS-grade for sensitive electronics); the L2 output transfers in about 40 milliseconds.

Who the Quattro-II 2x120V is built for

• Cruising boats and yachts with shore power and a generator - the Quattro auto-selects between the dock and the genset, with seamless changeover, and supplies 120/240V split phase to the whole panel.
• Liveaboards and larger cruisers with 240V loads - a water heater, range, dryer, or 50A/240V inlet gets split phase from one box, with a generator input ready for off-dock cooking and AC.
• Off-grid homes and cabins with a backup generator - a compact split-phase inverter/charger for a 120/240V panel, with solar and a genset both feeding the same unit; ESS-ready via anti-islanding.
• Installers and electricians - VE.Bus communication, VEConfigure, and parallel/three-phase scaling to larger VE.Bus systems.

Why this is the Quattro-II 2x120V

Two AC inputs with an integrated transfer switch

Connect shore power and a generator directly. The Quattro-II selects the active source automatically - no external automatic transfer switch to buy, size, or wire.

Split phase from a single enclosure

Rather than paralleling two inverter/chargers (one per leg), the 2x120V handles both legs in one box - simpler wiring, one VE.Bus device, less panel space. It feeds through 120/240V when shore or generator power is present, and supplies 120V on both legs in inverter mode.

PowerControl and PowerAssist

Set a maximum shore or generator current and the unit uses only the leftover capacity for charging, so the inlet breaker never trips (PowerControl). When a peak load exceeds the inlet rating, it supplements from the battery and recharges once the peak passes (PowerAssist, on the L1 input). An optional external 100 A current sensor extends PowerControl/PowerAssist to shared circuits.

Two AC outputs

The main output is no-break for critical 120V loads. The second (auxiliary) output is live only when an AC source is present - so non-critical loads like a water heater can't discharge the battery overnight. Auxiliary output is rated 50 A per leg.

Adaptive multi-stage charging - lithium and lead-acid friendly

A four-stage charge profile (bulk, absorption, float, storage) with adaptive-charge software and an included battery temperature sensor, fully programmable for lithium, AGM, gel, and flooded banks. Maximum charge current is 120 A (12V) or 70 A (24V).

ESS-ready with built-in anti-islanding

Built-in anti-islanding and a growing list of grid-code approvals let the 2x120V run a Victron Energy Storage System - self-consumption, peak-shaving, or grid backup - alongside SmartSolar MPPTs and a lithium bank.

Scales with your system

Up to six units run in parallel on a single VE.Bus for higher output, and three units configure for three phase (note: in multi-phase setups the L2 output is disabled on all units).

Monitor and control from anywhere

Add a Cerbo GX or Ekrano GX and your system is visible in the free VRM Portal from your phone, tablet, or laptop. Configure on-site with VEConfigure (via the MK3-USB interface) or the VictronConnect app over Bluetooth (via the VE.Bus Smart dongle).

Available variants

All variants are sold on this page - choose your battery voltage from the variant selector above. Both are 3,000 VA / 2,400 W continuous, 5,500 W peak.

Model	Battery	Cont. output at 25 C	Peak power	House charger	AC inputs
Quattro-II 12/3000/120-50/50 2x120V	12 VDC	2,400 W (3,000 VA)	5,500 W	120 A	Two
Quattro-II 24/3000/70-50/50 2x120V	24 VDC	2,400 W (3,000 VA)	5,500 W	70 A	Two

Not sure which fits your bank? Get a custom quote from our Seattle team or book a system consultation and we'll size your inverter, charger, batteries, and cabling together.

Full technical specifications

Inverter (inverter mode)

• DC input voltage range: 9.5 - 17 V (12V), 19 - 33 V (24V)
• Output voltage: 120 VAC +/- 2% (120V single phase in inverter mode; L1 and L2 internally linked)
• Output frequency: 60 Hz +/- 0.1% (adjustable to 50 Hz)
• Waveform: pure sine
• Continuous output at 25 C: 2,400 W (3,000 VA)
• Continuous output at 40 C: 2,200 W
• Continuous output at 65 C: 1,700 W
• Maximum apparent feed-in power: 2,500 VA
• Peak power: 5,500 W
• Maximum efficiency: 93% (12V), 94% (24V)
• Transfer time: under 18 ms (L1 output), approx. 40 ms (L2 output)

AC inputs and pass-through

• Two AC inputs with automatic source selection (e.g., shore power and a generator)
• Split-phase input: 180 - 280 VAC, 45 - 65 Hz
• Single-phase input: 90 - 140 VAC, 45 - 65 Hz
• Transfer switch: 50 A
• Maximum AC input current: 50 A each leg
• 240 VAC output available only when fed from a split-phase source
• External AC current sensor (optional): 100 A

Charger

• Adaptive 4-stage charging: bulk, absorption, float, storage
• Lithium-ion compatible
• Absorption voltage: 14.4 V (12V) / 28.8 V (24V)
• Float voltage: 13.8 V / 27.6 V
• Storage voltage: 13.2 V / 26.4 V
• Maximum charge current: 120 A (12V) / 70 A (24V)
• Battery temperature sensor included

AC OUT-2 (auxiliary output)

• Live only when an AC source is present - switches off when shore/generator power is lost
• Rated 50 A each leg
• Typical use: water heaters, air conditioning, or loads that shouldn't run from the battery bank

System and communication

• VE.Bus port for parallel and three phase operation, remote monitoring, and system integration
• Two general-purpose communication ports (e.g., lithium-battery BMS integration)
• One programmable relay - general alarm, DC under-voltage, or genset start/stop (AC 120 V / 4 A; DC 4 A up to 35 V, 1 A up to 60 V)
• Remote on/off input
• Compatible with Cerbo GX, Ekrano GX, Digital Multi Control panel, VE.Bus Smart Dongle (Bluetooth), and MK3-USB interface
• Configurable via VEConfigure and VictronConnect

Protection

• Output short circuit
• Overload
• Battery voltage too high or too low
• Over-temperature
• 120 VAC on inverter output
• Excessive input voltage ripple

Enclosure and environment

• Material: steel, RAL 5012 blue
• Protection category: IP22
• Operating temperature: -40 C to +65 C (fan-assisted cooling)
• Humidity (non-condensing): 95% max
• Battery connection: 2x2 M8 bolts (12V), 2 M8 bolts (24V)
• AC connection: 4 AWG (21 mm2) screw terminals
• Weight: 52 lb (12V), 50 lb (24V)
• Dimensions (h x w x d): 23 x 13 x 7 in (579 x 319 x 168 mm)

Standards and certifications

• Safety: EN-IEC 60335-1, EN-IEC 60335-2-29
• EMC: EN 55014-1, EN 55014-2, EN-IEC 61000-3-2, EN-IEC 61000-3-3, IEC 61000-6-1, IEC 61000-6-2, IEC 61000-6-3

Recommended accessories

• Cerbo GX or Ekrano GX - system controller and VRM gateway
• BMV-712 Smart or SmartShunt - battery state-of-charge monitoring over Bluetooth
• MK3-USB interface - configure the unit from a laptop via VEConfigure
• 100 A external AC current sensor - extend PowerControl and PowerAssist to shared circuits
• Compatible lithium battery banks from Victron, Epoch, and MG Energy Systems
• Victron SmartSolar MPPT - pair to build a full ESS system

Installation and sizing help

Wiring a split-phase Quattro-II isn't plug-and-play. Battery cable sizing, fusing, AC inlet ratings (you have two inputs to plan for), and bonding all need to match the variant you choose. Two free resources to start with:

• Victron Wiring Unlimited - the canonical reference for sizing the DC and AC sides of a Victron system.
• Our AWG to Metric Conversion chart.

If you want a second set of eyes on your one-line diagram, our certified technicians do system consultations and full custom quotes. Email support@bluemarine.com or call (800) 628-6306.

Frequently asked questions

What's the difference between the Quattro-II 2x120V and the MultiPlus-II 2x120V?

Both are single-box 120/240V split-phase inverter/chargers. The MultiPlus-II 2x120V has one AC input; the Quattro-II 2x120V has two AC inputs with automatic source selection. Choose the Quattro-II if you run both shore power and a generator (or two generators) and want the unit to switch between them automatically.

Can I get 240V when running off the battery?

No. In inverter mode the unit outputs 120V on both legs (L1 and L2 internally linked), so 120V loads on either leg keep running. 240V is only available when the unit is fed from a split-phase 120/240V shore or generator source - this is by design, to keep heavy 240V loads from draining the battery. If you need true 120/240V split phase off the battery, install two standard 120V Quattro units in parallel (one per leg).

Is it lithium battery compatible?

Yes. The charger supports custom voltage and current profiles for LiFePO4 and other lithium chemistries, and it communicates with Victron's VE.Bus BMS over the communication port.

Why does the L2 output transfer slower than L1?

The L1 output switches in under 18 milliseconds - fast enough that sensitive electronics ride through the transition. The L2 output transfers in about 40 milliseconds. Put your critical, sensitive loads on L1.

What warranty does it come with?

A 5-year limited warranty from Victron Energy, upgradable to 10 years for an additional 10% of the purchase price. Blue Marine handles the warranty claim process for you. Email support@bluemarine.com.

Why buy your Quattro-II 2x120V from Blue Marine

• True Blue Victron Energy Distributor - we carry the full Victron line and know the products inside out.
• Certified technicians on the phone - (800) 628-6306 for sizing, troubleshooting, and warranty support.
• Free shipping over $49 from our Seattle warehouse.
• 60-day hassle-free returns.
• Local pickup available in Seattle, WA.
• Custom quotes and full system design - we'll spec the inverter, batteries, MPPTs, cabling, and monitoring as one package.
• Dealer and installer program with trade pricing. Apply here.